Pulsation control



May 5, 1931.

| E. cRowE PULSATION CONTROL Filed June 22, 1928 2 Sheets-Sheet 4/03/41 A. 4 [Fare ATTORNEY Patented May-*5, 1931 UNITED, STATES PATENT OFFIE LLOYD I. E. GRBWE, OI MILWAUKEE, WISCONSIN PULSATION oon'raor.

Application filed June 22,1925. Serial No. 287,478.

This invention relates to internal combustion engines of the two cycle type and has for an object the provision of means for controlling the pulsations or surges of the in coming air for the fuel mixture in en 'nes having air intake ports, and for contro ling the pulsations or surges of the exhaust gases for engines taking air through the crank case, as well as for engines of the type first 1o referred .to which employ separate air intake ports.

With the above and other objects in view,

the invention further includes the following 25 view taken longitudinally through the exhaust ip Figure 3 is a sectional view showing a modified form of the invention wherein the exhaust pipe is provided with 'a water jacket.

Figure 4 is a section on the line 4-4 of Figure 3.

Figure 5 is a fragmentary view showin the lower end of the vacuum chamber wit the elbow removed.

Figure 6 is a diagram illustrating the action of the air enteringthe engine cylinder and the returning pulsation of the exhaust gases when the piston is at the beginning of its compression stroke. 1

Figure 7 is a like view with the inlet port closed and the outlet port partly open.

In engines of the two cycle type, the exhaust ses leave the cylinder and pass out throng the exhaust pipe, leaving behind them a partial vacuum. This is quickly followed by a surge back and a portion of the gasesrushesinto this vacuumand prevents thorough scaven M This backwar and forward surge or pul- 'sation of the exhaust gases is taken care of g of the engine cylinder.

in the present invention by providing a vacuum chamber 10 which is connected in the exhaust pipe 11 of the engine and extends from said plpe.

As the exhaust gases rush past the open- I ing 12 at the inner end of the vacuum chamber 10, a partial vacuum is created within this chamber due to the suction behind the gases. -When a back surge occurs, the returning gases will rush into the chamber 10 in which a partial vacuum has been created and will thus be prevented from reaching the exhaust port of the engine. The next outward surge or impulse of the gases will recreate this partial vacuum within the chamber 10 and the'operation will be repeated.

Free outward travel of the exhaust gases will thus be insured.

As shown in Figure 6 of the drawings, air enters. the engine cylinder with the inlet and 7a outlet ports open, the exhaust gases. havmg just left the cylinder so that a partial vacuum has been created within the chamber 10 due to the suction of the exhaust gases passing outward throu h the exhaust p1 back surge of t e exhaust gases wi l fill the chamber 10 and will also enter that rtion of g the exhaust pipe between the cham r 10 and' the engine cylinder. The piston is now moving upward on the compression stroke, clos 3o ing t e-inlet port before the outlet port is fully closed. During-this movement of the piston, the returning exhaust gases WhlOh have entered the chamber 10 from the exhaust pi e, build up a wall or barrier upon the out- 35 si e of the partly closed outlet port and oppose the outflow of air under compresslon through said port, there being in efiect opposmg pressures upon opposite sides of the outlet port so that the full charge of air is retained within the cylinder. 4 In order to regulate the capacity of the chamber 10 in accordance with the needs and requirements of the engine, the chamber comprises an inner stationary section 13 and an 95, outer relatively movable section 14. The section 14 is adjustably mounted upon the section 13 and is held in adjusted pos1t1on through the medium of set screws 15. The

end of the section 14 which surrounds the The 75. V

section 13 is provided with a packing gland 16 so asto form a leakproof joint. j( In Figure 3, the vacuum chamber extends from an exhaust pipe 17 and the latter is provided with a water jacket 18 so as to cool the pipe. The exhaust ort 19 of the engine is in communication wit the vacuum chamber 10 through a pipe 20 and extending from the lower open end of this pipe is an elbow 10 gl. As shown in I Figure 4, this elbow is curved and its inner end is bolted to the pi 20 as shown at 22. The elbow may thus removed from the .pipe and be arranged to extend in a direction opposite to that shown 15 in Figure 4, if desired.

It 1s of course apparent that the chamber" 10 may be non-ad ustable, in which case its capacity would be regulated in accordance with the character of the engine. It may also be found desirable to provide a water jacket on both the adjustable and non-adjustable forms of the chamber 10.

The invention is susceptible of various changes in its form, proportions and minor i details of construction and the right is herein reserved to make such changes ate-properly fall within the scope of the appended c aim.

Having described the invention what is claimed 1s: r I In aninternal combustion engine, a cylinder having inlet and exhaust orts, an exhaust pipe leading from the e aust port, a vacuum chamber within the exhaust pipe and havin communication with the exhaust port, and a justable means. providing communication between the exhaust, port andpipe and the vacuum chamber and pi to control the direction of travel of the. ex aust gases.

In testimony whereof I aflix m si ature.

m LLOYD L. E. R WE. 

